As an electric power steering device that assists the steering operation of an automobile, an example thereof is described in Patent Document 1 such that the electric power steering device includes: a housing having therein a worm gear mechanism that transmits rotary torque of an electric motor to a steering shaft, as a steering assist force; and a motor control unit that controls the electric motor. However, in the electric power steering device described in Patent Document 1, since the electric motor and the motor control unit (ECU) are electrically connected via external wiring such as a harness, the electrical connection work has to be conducted separately from the assembling work of the electric motor or that of the motor control unit. This causes a drawback of poor workability.
Accordingly, there is another proposal of forming a plate-shaped connection terminal of the motor control unit to be integrally attached to the electric motor, and then forming a contact surface at the plate-shaped connection terminal so as to be in face contact with a connection terminal of the electric motor (see Patent Document 2).    Patent Document 1: JP 2002-127921 A    Patent Document 2: JP 2006-166630 A
It should be noted that, however, the electric motor and the motor control unit are electrically connectable without the provision of the external wiring such as a harness, in the electric power steering device disclosed in Patent Document 2. However, the contact surface formed at the plate-shaped connection terminal of the motor control unit protrudes on the electric motor side from the surface, where the motor is installed, provided in the motor control unit. It is therefore necessary to separately arrange a space for causing the connection terminal on the motor side to be in face contact with the connection terminal on the control unit side. This causes a drawback of increasing an occupied space. There is another drawback of necessitating a cover for covering the plate-shaped connection terminal of the control unit in order to prevent short-circuit between the terminals or prevent the adhesion of dusts. This also leads to further another drawback of increasing the number of parts.
The present invention has been made in view of the above-described drawbacks, and has an object of providing an electric power steering device whereby an electric motor and a motor control unit are electrically connected with ease and the electrical connection between the electric motor and the motor control unit is suppressed from influencing to assembling of any other part.